Here is another New York Times article. This one touches on some of the themes that keep coming up in the income inequality discussion, such as the role of the global economy, education, government taxes policy, and the changes in the income distribution during the last 30 years:

. . . From World War II through the 1970s, while most Americans were getting solid raises every year, the incomes of the richest 1 percent were doing only a little better than inflation. Since the 1980s, the two groups have switched places. The affluent have received huge gains, and everyone elseâ€™s pay growth has slowed down. For the last six decades, in other words, the American economy has been much more of a zero-sum game than we might like to believe.